Acoustic Emission Generated during Tensile Deformation of Corson Alloys

Abstract

Acoustic emission generated during tensile deformation of Corson alloys which are known as age-hardened copper alloys was studied.
Continuous type acoustic signals were monitored. The mean voltage took a maximum at the yield point during the tension test. Acoustic energy per unit particle increased as the square of the distance between the centers of two neighboring particles increased. This suggests that the effective dislocation length against one precipitate particle is roughly proportional to the distance between the centers of two neighboring particles. The lower frequency ratio of acoustic energy at two different frequencies increased as the radius of the precipitate particle increased. This suggests that the effective distance of the dislocation movement, which can be regarded as the acoustic source, increases as the radius of the precipitate particle increases, and the diameter of the particle may be corresponding to the effective distance of dislocation movement which can be regarded as accoustic source. From the variation of mean voltages at two different frequencies during the tension test, it was suggested that micro yield occurred at the position of the smaller particle at a lower stress and the position of the larger particle at a higher stress.